Vending machines for dispensing hot beverages contain hot water tanks for heating water which is subsequently discharged through an outlet into a cup or product mixing bowl. In this regard, see U.S. Pat. 4,632,274. In such vending machines, the hot water tank may comprise a discharge carrying a seat covered by a seal reciprocated from a position covering the seat to a position spaced from the seat of the discharge permitting fluid to leave through the discharge from the hot water tank.
Controlled heating of water in the tank (by for example a heating element) causes precipitation of lime from the water which precipitates onto the seal, the discharge outlet walls or other surface inside the hot water tank. In some cases, the precipitated lime (grit) becomes lodged on top of the seat and between the seal and mouth of the discharge outlet degrading the seal, permitting water drip from the opening created between the seal and seat of the discharge--a notorious problem in the vending machine business particularly in humid areas.
In an attempt to overcome this problem, the shape of the seal was altered to carry a sloping peripheral sealing edge angled to the wall of the seat of the discharge so that the engagement of the sloped wall or edge of the seal on the seat creates a "wiping" action on the seat to remove the lime precipitate (grit) to ensure the seal the discharge outlet. Unfortunately, the proposal still permitted lime to precipitate.
Applicant is aware of the following patents--U.S. Pat. Nos. 4,094,233 (which corresponds to Canadian Patent 1,056,613), 4,143,589; 4,305,328; 4,433,617; and 4,662,271.
U.S. Pat. No. 4,094,233 (and Canadian Patent 1,056,613) teaches the shifting of the elevation of a collar 46 to adjust the shutoff water level 29 to vary the quantity of hot water that is transferred to the tank 18 for coffee brewing purposes.
U.S. Pat. No. 4,143,589 teaches the use of tube 26 adjustable for the purposes of the strength of coffee and the use of an air compressor which delivers air to a metering chamber to force heated water therefrom into the brewing chamber.
U.S. Pat. No. 4,305,328 teaches the use of an air compressor 17 for delivering compressed air via line 19 to the brewer to force brewed coffee from the brewer through line 13 to mixing bowl 11 and lifting of a line 13 (e.g. portion 13a) higher than that of screen 57 to half the flow.
U.S. Pat. No. 4,433,617 teaches the shutting off of an outlet pipe by a shutoff device.
U.S. Pat. No. 4,662,271 teaches the use of permanent magnet to move a sealing lid or cone 21 to provide an annular gap through which the water can flow.
While the above relate to coffee brewers and components, none deal with the problems created by the precipitation of lime (grit) destroying seals. Nor is Applicant aware of any solution that has overcome the problem of lime precipitation and the destruction of the seal of the discharge outlet.
It is therefore an object of the invention to provide an improved valve mechanism for transferring fluids or fluidized material from storage which when deactivated precludes the fluid or fluidized material from further discharge and overcomes the eventual "dripping" problem.
It is a further object of the invention to provide such valve mechanism which is easily manufactured, mounted and is reasonable in cost.
It is a further object of the invention to provide a vending machine for dispensing hot beverages which comprises such valve mechanism.
It is a further object of the invention which permits the discharge to be evacuated of water when water is precluded from entering the discharge.
It is a further object of the invention to provide a valve mechanism in a vending machine whose useful life does not depend on the hardness (lime content) of the water at the location of the machine.
Further and other objects of the invention will be realized by those skilled in the art from the following summary of the invention and detailed description of embodiments thereof.